Chimney Bees in Elyria Canyon Park

Mining Bees in Elyria Canyon Park Location: Elyria Canyon Park, Mount Washington, Los Angeles, California May 18, 2014 11:00 AM So, walking back from the Elyria Canyon Work Party this morning, I was tasked with taping off the Indian Milkweed above the ranger station, and upon getting ready to leave, I noticed small perfectly round holes, slighting smaller in diameter than a standard pencil, in the hard packed earth of the trail.

Chimney Bee Holes

I thought if I was patient, I might get to see the tenants. After several minutes, I heard a buzzing and watched a small winged creature disappear into one of the holes. I eventually got images of a Mining Bee’s head, several images of a Mining Bee excavating with only the abdomen showing, and an image of a pollen ball that has been gathered by the bee.

Head of a Chimney Bee preparing to exit

According to BugGuide: “Female digs long branching tunnel in soil, prepares brood cell at the end of each branch, and stocks cells with pollen balls and nectar. 1 egg is laid on pollen ball in each cell, then cell is sealed. Larvae develop rapidly and pupate in cells. 1 generation a year.” BugGuide also states: “Many small, ground-nesting bees observed in areas of sandy soil are members of the family, Andrenidae. Characteristics of this family (of which there are approximately 3000 species) are: Small size, 20 mm, (or smaller) brown to black in color, and nesting in a burrow in areas of sparse vegetation, old meadows, dry road beds, sandy paths. Although the nests are built in close proximity of one another, the bees are solitary (each female capable of constructing a nest and reproducing). Many species are active in March and April when they collect pollen and nectar from early spring blooming flowers. The female bee digs a hole 2-3 inches deep excavating the soil and leaving a pile on the surface. She then digs a side tunnel that ends in a chamber (there are about 8 chambers per burrow). Each chamber is then filled with a small ball of pollen and nectar. An egg is laid on the top of each pollen ball and the female seals each brood chamber. The emerging larval bees feed on the pollen/nectar ball until they pupate.”

Chimney Bee excavating

Now that I was made aware of the nests on the trail, I saw several other areas that evidenced the development of a Colony of Mining Bees. The Mining Bees are very quick and wary, and it was impossible to capture an image of the full body of an individual.

Chimney Bee Excavating

Comment from Clare Marter Kenyonso good to know they are still around. the last place i saw them was on the pathway from the barn to the trail half way to elyria! NICE! c.

Pollen Ball of a Chimney Bee

I explored looking for bush lupine – going along dirt glenalbyn and then from Westpoint hiking down and am sorry to say I could not find any plants. I did see some coffee berry though Lynnette

Update: The following comment just arrived on another posting, referring to this posting.January 16, 2016 Also, in regards to the archived post, I think those are actually Diadasia (unaware of a common name), and not mining bees (genus Andrena). What a cool find, impressive since it’s so tiny!

Following up on this comment, we learned on BugGuide that the genus Diadasia is in the subfamily Emphorini, Chimney Bees. This BugGuide posting looks very similar.